Free speaker score! But do I "upgrade"?

Hey all. Scored myself some Mission 760i SE speakers today, fully working, for free!

They do sound nice with my Technics SU-VX600 amp. I'm sending both A&B signals to each speaker, for the LF and HF terminals.

However: I've got a relatively large living room and I'm wondering if I should stick with these, or continue looking for better, bigger speakers? I listen to a wide variety of music styles and would like a clean, wide sound stage.

My options are as follows:

• KEF Q15
• Celestion DL6
• Mission 782 (these might not be available - seller is ghosting me)

What do you think? Stick or twist?